Nintendo Wi offers several shooting games, first person shooters, multiple guns including a shotgun, tommy-gun and pistol configuration. Better than nothing...
You can weigh the various zappers (including the original one from duckhunt) down with lead tape, fishing weights, etc. to get the toy gun to a more realistic weight.
An intense weekend course with a respectable instructor/school might do wonders. At home you can dry fire, practice reload/clearing/drawing drills to build muscle memory.